I don't know anything about wine and, not being a drinker, wonder if people really can tell the shades of difference in finer vintages (naturally I'm sure they can discern screw-top junk from well-grown stuff under corks). I'm fascinated by viniculture and the episodes of any show that explores it (though my favorite is "Vintage Steele" from "Remington Steele.")
Ignoring the crime(s) and story, I love the trappings and some of the fascinating characters introduced. They could have been a little nuttier (I'm sure wine-tasting can really shake the nuts from the trees). But overall this episode is inoffensive and enjoyable. It even involves some actual detection. And it's not written over the heads of people who wouldn't know fine wine from ditch-water, though drinking too much ditch-water doesn't get one drunk.